JPH02502000A - Differential pressure control mechanism for dual brake valves - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Differential pressure control mechanism for dual brake valves The present invention is based on U.S. Patent Application No. 831.891 filed February 24, 1986; Continuation-in-part of U.S. Patent Application No. 876.154, filed June 19, 1986 It is.

The present invention relates to a dual brake valve for a pneumatically operated brake system.

Modern brake circuits allow the vehicle's service brakes to function even if one circuit fails. Requires a separate and independent brake circuit to ensure motion. independent blur The pressure in the key circuit is controlled by a dual brake valve. This valve is a brake When activated, the main pressure is actuated by an ordinary pedal mounted inside the vehicle's cab. and the auxiliary brake circuit at the same time. A typical conventional two-system brake valve Disclosed in U.S. Patent No. 3,580,646, issued May 25, 1971 .

This type of valve minimizes the inherent continuous operation of the main and auxiliary brake circuits. Both are designed to minimize pressure differences between the main and auxiliary brake circuits. must be maintained. Therefore, it is necessary to minimize the "opening" force of the auxiliary brake circuit. There is a point. In the above patent, this consists of two opposing springs, special bolts and nuts. This is done using a bolt and spring retainer. This mechanism is clearly very It's complicated. No. 876.154, filed June 19, 1986. The device disclosed in the No. A differential spring and plunger are used for this purpose. Main pressure referred to as “differential pressure” The pressure difference between the brake and auxiliary brake circuits is very sensitive to differential spring loading. I understand. Two completely separate valves with short or long differential springs due to tolerances The effective length of the spring space in these valves is equivalent to It can be different. Therefore, the resulting spring load increases or decreases . The present invention includes a spring retainer that snaps into the stem of the relay piston. In use, the load on the differential spring can be precisely controlled. vinegar Since the length of the pull retainer can be controlled relatively easily, the resulting differential Spring force is also controlled. Therefore, more precision of the differential pressure between the main and auxiliary brake circuits control is possible. The above and other features of the present invention will be described below with reference to the accompanying drawings. It will be clear from the description.

FIG. 1 is a longitudinal cross-sectional view of a dual-system brake valve constructed according to the present invention, and FIG. 2 shows a schematic view of the brake valve of FIG. 1 taken substantially along line 2-2 of FIG. FIG. 3 is a cross-sectional view of the pull retainer.

In the drawings, the dual brake valves generally designated by the reference numeral 10 are generally designated by the reference numeral 14. It includes a housing 12 defining an aperture as shown. The hole 14 has a large diameter portion 16 and a small diameter portion 18. It is stepped to define the A control drive member generally designated 20 or A plunger device is slidably fitted within the bore 14. The control drive member 20 is the main includes a piston 22, the main piston 22 protruding radially from the piston and It includes a support portion 24,26 extending circumferentially thereabout. Support part 24.26 supports a circumferentially extending seal 28°30. Support part 24 and seal 28 is slidably engaged with the large diameter portion 16 of the bore 14, and the support portion 26 and the seal 30 are It slidably engages the small diameter portion 18 of the hole 14 .

The support portion 24,26 cooperates with the wall of the bore 14 and the main piston 22 to provide a space between them. An inlet chamber 32 is defined that communicates with an inlet 34. The support portion 24 is the large diameter portion of the hole 14 The support portion 26 is slidably fitted within the small diameter portion of the hole 14 and the support portion 26 is slidably fitted within the small diameter portion of the hole 14. As it is fitted in the main piston 22, an effective area is defined in the main piston 22. Entrance 34 The air pressure acting on this effective area communicates through the control drive member 20 in FIG. Force upward.

The control drive member 20 further includes an actuation pedal (not shown) mounted in the driver's cab of the vehicle. a pedal plate 3-6 engaged with the pedal plate 3-6, the actuating pedal being engaged with the pedal plate 36 when the brake is applied. Apply a downward force to. A compensating spring 38 connects the pedal plate 36 to the main piston 22. Engage with the installed stop ring 40. The main piston 22 further includes a valve poppet 4 4, the valve poppet defining an internal bore 42 for slidably receiving the valve poppet 4; It supports an extending seal member 46. The spring 50 is attached to the main piston 22. Valve poppet 44 is sealingly engaged against supported valve seat 48. Valve seat 48 is located in a recess 52 extending circumferentially around the lower part of the main piston 22 in the figure. a circumferentially extending ring that is housed and held in place by a retaining ring 54; be. Therefore, the control drive member 20 includes the main piston 22, the valve poppet 44, and the valve seat 4. 8. Separation consisting of springs, seals, retaining rings and retaining rings assembled on these It is a removable cartridge.

This cartridge can be installed and removed as a unit when servicing the valve, and when manufacturing the valve. Can be installed in the housing 12 as a unit and thus manufacture and service the valve arrangement 10 is facilitated.

The housing 12 further includes a main portion housing the control drive member 20 and a side portion. including an inwardly extending septum 64 that partitions the ring. The partition wall 64 is supported by the poppet 44. a circumferentially extending valve seat 66 positioned to engage seal 46; It is equipped with The bulkhead 64 cooperates with the main piston 22 to provide an outlet for the main circuit between them. Alternatively, an annular delivery chamber 68 communicating with the delivery lower 0 is formed.

The bulkhead 64 is slidable over a support portion 74 of the relay drive member, generally designated 76. A hole 72 is defined therein. Relay drive member 76 further slides into portion 80 of hole 14. It includes another movably engaged support portion 78. The drive member 76 cooperates with the bulkhead 64. act to define a relay chamber 82 therebetween which communicates with the delivery chamber 68 via an opening 84. to be accomplished. Relay drive member 76 further projects into an opening defined in annular poppet 44. It includes a protruding stem 86 that extends. The stem 86 has an elongated opening 88 that allows the housing to At the exhaust port generally designated by the reference numeral 87, which is provided at the bottom end of the engine 120, The delivery chamber 68 is brought into communication. The relay drive member 76 defines a passage 89 therein. , the passage cooperates with a passage 90 defined in an annular poppet member 92 to open an opening 88. It communicates with the exhaust port 87.

Poppet 92 is slidably fitted within a hole 94 defined in housing 12 and is circular. It supports a seal 96 extending in the circumferential direction. The spring 98 is the poppet member 9 2 into sealing engagement with the annular valve seat 100. Valve seat 100 is similar to valve seat 48. and is secured within a circumferentially extending recess 102 provided in the wall of the housing 12. It consists of an annular ring that is removably held by a hoop 104. Relay drive part The member 76 is provided with a valve seat 106 extending in the circumferential direction at its lowermost end in the figure. When the drive member 76 is pushed downward in the figure, the valve seat sealingly engages the seal 96. It is supposed to be done.

The inlet or supply port 10g was connected to the auxiliary brake system and supported by the poppet 92. The engagement of the seal 96 with the valve seat 101) allows flow into the normally closed inlet chamber 110. Connect the body. The relay drive member flow cooperates with the housing 12 to A delivery chamber 112 communicating with a delivery port 114 connected to a sub-brake circuit is defined between the do.

A reaction force transmission mechanism, generally designated 116, is coupled to the end 120 of the control drive member 22. It is attached to the end 118 of the relay drive member 76 facing the opposite direction. The mechanism 116 has both ends The portions have inwardly projecting lips 124, 126 defining flexible portions 123, 125. The spring retainer 122 includes a generally C-shaped spring retainer 122.

As shown, the end 11B of the relay drive member 76 has a groove 128 extending in the circumferential direction. It is equipped with Groove 128 allows retainer 122 to snap onto the end of relay drive member 76. When the lips are mated, the lips 126 are received. The retainer 122 is connected to the relay drive section. Prior to installation into material 76, plunger 130 is installed within retainer 122.

A spring 132 abuts the end 1119 and is defined in the plunger 130. The plunger is brought into engagement with the lip 124 by abutting the shoulder 134 . plan The jaw 130 projects above the end of the lip 124 and extends over the end 12 of the control drive member 22. 1 includes a protruding portion 136 that can be engaged with 0. As shown in FIG. 125 is deflectable to cause lip 126 to snap fit into groove 128. Wear.

In operation, numerous components of valve 10 are activated when the vehicle's brakes are released. Illustrated in the position it occupies. In this state, the supply air passes through the inlet 34 to the inlet chamber. 32. However, the spring 50 holds the seal 46 against the valve seat 48. Because the pressure is applied to the valve housing 12 through the inlet 34, no additional fluid pressure is applied into the valve housing 12 through the inlet 34. Communication has been cut off. As mentioned above, the unbalance area of the control drive member 20 Therefore, the air pressure communicated with the chamber 32 acts on this unbalanced area and the control drive member 2 0 to bias the control drive member to the position shown. At the same time, the air It communicates with an inlet chamber 110 via a supply port or inlet 108 via a secondary brake circuit.

The sealing engagement of seal 96 and valve seat 100 allows valve access through inlet or supply port 10B. Further communication of air pressure into the housing 12 is blocked. Sending lower 0 and sending Chamber 68 communicates with exhaust port 87 via slot 88 and passages 89 and 90.

Similarly, the outlet 114 and the outlet chamber 112 are communicated with the exhaust port 87 via the passage 90. There is.

When applying the brakes, the driver operates the pedal and moves the pedal plate 36 downward in the figure. partially compress the compensating spring 38. Therefore, the main piston 22 is also pushed downward to bring the seal 46 into sealing engagement with the valve seat 66, causing the delivery lower 0 and Communication with the exhaust port 87 is cut off. Seal 46 engages both valve seat 66 and valve seat 48 This position is referred to as the "wrap position."

When the control drive member 20 is moved to the wrap position, the main power to the relay drive member 76 is Movement of the piston 22 causes the protruding portion 136 of the plunger 130 to move into the control drive member 20. It will be engaged with the end portion 120. Therefore, between the protruding portion 136 and the end portion 120, The engagement disengages the plunger 130 from the lip 124 so that the spring The force of the relay drive member 132 is transmitted to the relay drive member flow, which is shown in FIG. the valve seat 106 into sealing engagement with the seal 96.

The force of spring 132 is due to the force of spring 98 and the fluid pressure within chamber 110. Since the load force is less than the applied load force, the seal 96 is separated from the valve seat 100. It won't happen. However, the force of spring 132 is greater than the force of spring 98. Since the force is only somewhat smaller, the force that forces seal 96 into engagement with valve seat 100 is proportional. In order to separate the seal 96 from the valve seat 100, the minimum "opening" ” Just apply force to the poppet 92.

Further movement of the pedal plate 36 downward in the figure causes the valve seat 48 to separate from the seal 46. is sufficient to cause the seal to remain engaged with the valve seat 66. Therefore, fluid pressure is communicated from the inlet 34 to the outlet or outlet lower 0 via the valve seat 48.

However, the lowermost surface of the main piston 22 does not reach the fluid pressure level within the delivery chamber 68. The high pressure generated in the delivery lower 0 reacts against the main piston 22. act.

Therefore, the force applied to the main piston 24 by the fluid pressure of the delivery lower 0 is until it balances the compression force of the spring 38 generated by the actuation of the pedal in the The control drive member 20 is pushed upward in the figure. At the same time, the increased pressure in the delivery chamber 68 is communicated with the relay chamber 82 through the opening 84, and acts on the relay drive member 76 to drive the part. Push the material downward in the diagram. The relay drive member 76 has already been moved to the wrap position. Since the force exerted by the spring 98 is substantially released, the valve pop The valve seat 96 is immediately isolated from the valve seat 100 to communicate pressure to the outlet port 114. Can be done. Therefore, when the pressure in the delivery chamber 112 balances the pressure in the relay chamber 82, Poppet 92 can be returned to the wrap position.

If the vehicle operator increases the force on plate 36, the additional pressure is applied as described above. will be communicated with the delivery lowers 0 and 114. The force on plate 36 is reduced and compensated. When the compression force of the spring 38 is reduced, the high pressure of the delivery lower 0 will cause the main piston to 22 to open the valve seat 66, and the pressure at the delivery lower 0 is applied to the compensation spring. Fluid pressure can be vented through exhaust port 87 until it is again balanced with the compressive force of ring 38. When the balance is achieved as described above, the valve member returns to the wrap position. similar pressure change This also occurs in the relay chamber 82 and controls the pressure in the subcircuit.

When the vehicle's brakes are released, the compensating spring returns the pedal plate 36 to the position shown. vinegar. The high pressure within the inlet chamber 32 returns the control drive member 20 to the position shown. relaypi The stone 76 is returned to the position shown by the high pressure within the delivery chamber 112, and the pressure is exhausted. It escapes into the atmosphere through the air vent 87.

FIG. 2 Copy and translation of corrected statement) Submission form (Patent Law Jlr Article 184-8) July n, 1989

Claims (1)

[Claims] 1. A housing having a pair of inlets and a pair of outlets cooperating with a corresponding one of the inlets. a pair of valve members controlling communication between each inlet and a corresponding outlet; one of the members, and is slidably fitted in the housing to read the above information. said one valve member being configured to initiate communication between one of the ports and the corresponding outlet; including a control drive member movable toward or from a position to be moved; A manual valve drive means is slidably fitted in the housing to release the valve. The control and drive member is supported within the housing to allow movement of the control and drive member away from each other. and actuate the other valve member in response to actuation of one valve member. a relay drive member that responds to the pressure difference between the two outlets, and both drive members. is supported on one side of the relay drive member and applies a predetermined force to the relay drive member when the manual valve drive means is actuated. a reaction force transmitting means for transmitting a reaction force to a , the reaction force transmitting means connects the opposite end of the one drive member to the opposite end of the other drive member. A spring retainer protrudes toward the remaining part, and a spring retainer inside the spring retainer. a slidably fitted plunger, and the plunger when the manual valve driving means is actuated; a spring that engages the opposite end of the other drive member to provide brake action; and the plunger engages the opposite end of the other drive member during brake actuation. By doing so, the force generated by the above spring is transmitted to the relay drive member. A two-system brake valve characterized by a dual-system brake valve. 2. In the dual brake valve according to claim 1, the spring retainer the spring has a radially inwardly projecting lip at one end; A plunger is engaged with the lip, and the plunger is attached to the spring retainer. protrudes from one end of the drive member and engages the opposite end of the other drive member when the brake is actuated. A two-system brake valve characterized by comprising: 3. In the dual brake valve according to claim 2, the one driving member is A relay driving member, and the other driving member is a control driving member. Dual system brake valve. 4. In the dual brake valve according to claim 3, the relay driving member is a fluid pressure responsive portion and an opposing end of the relay drive member protruding from the fluid pressure responsive portion; a stem terminating in a spring retainer; A two-line play characterized in that it includes means for coupling the Glytainer to the stem. Kiben. 5. In the dual-system brake valve according to claim 6, the coupling means a groove provided around the stem and protruding radially inward from the spring retainer. 5 lip, the lip being accommodated in the groove. Pleiki valve. 6. In the dual brake valve according to claim 5, the spring retainer an axial direction defined by a pair of opposing flexible portions of the spring retainer; the flexible portion includes an opening extending in a direction in which the lip snaps into the groove; A dual-system brake valve characterized by being able to bend to allow the valve to mate.